You preferred it back in the days when you wore an onion on your belt, because it was the style at the time?
Modern cars can't work without electronics- we couldn't have the performance, economy or emissions we currently do without them. Nor would they be as easy to diagnose (yes, the codes often make it easier, unless you're some dinosaur who is stuck in the 1960s)
I don't doubt that the move away from maintenance features is the
fact that the vast majority of people do two things- they only drive their cards SO long, and they don't do much if any maintenance themselves on them. So why should manufacturers spend more money to enable user maintenance? It doesn't sell cars, and it makes cars cost more. So they are moving away from it- it's more that consumers are pulling them in that direction than they're trying to push them in the other direction. Same thing with stuff like spare tires; I'm sure that the vast majority of people just call AAA or something, and never even use their donuts, much less a full-sized spare. Personally, that's where I draw my line- I want a real spare of some kind, not just a can of fix-a-flat. What happens if I get stranded out on
a road in the middle of nowhere with a big puncture? I'm out of luck for hours until someone else can show up and fix my tire.
And stop/start increases fuel economy by 5-7% and emissions by a commensurate amount. That seems like a huge win for a really minor set of changes.